As one seeks to increase the power output of a turbine engine of a given size, generally the process leads to increasing temperatures of the gases of combustion exiting combustor to the turbine nozzle which directs the gases against a turbine wheel to drive the same. Conventionally, the nozzles are formed of a plurality of vanes and such vanes, being in the gas stream, must survive the higher temperatures. It is also required that the vanes survive the thermal and mechanical loading that is placed on them during engine cycles. And, of course, some means must be employed to mount them in the proper location to perform their intended function.
Various means of cooling the nozzle vanes in turbine engines have been proposed. While many such ideas have been quite effective, the problem of vane cooling becomes particularly different in small gas turbine engines. For example, in one known type of engine made by the assignee of the instant application, the vanes are assembled with a combustor or rear shroud by rivet-like pins which have a thickness of but 0.2 inches. This readily demonstrates the small size of the components involved and indicates that the technique of using complex internal air passages within the vanes is not practical and/or extremely expensive.
The present invention is directed to overcoming one or more of the above problems.